Efforts to reduce dependence on fossil fuels for transportation fuel and as feedstock for industrial chemicals have been undertaken for decades, with a particular focus on enabling economic feasibility of renewable feedstocks. Heightened efforts are being made to more effectively utilize renewable resources and develop “green” technologies, due to continued long-term increases in the price of fuel, increased environmental concerns, continued issues of geopolitical stability, and renewed concerns for the ultimate depletion of fossil fuels.
Cellulose in biomass is commonly used as a feedstock for biofuel production. For example, cellulose can be used to produce ethanol. Cellulose can also be used to produce furan-based biofuels by way of 5-(halomethyl)furfural, such as 5-(chloromethyl)furfural (CMF). CMF can be converted into 5-(ethoxymethyl)furfural, a compound considered as a promising diesel fuel additive. Alternatively, CMF can also be converted into 5-methylfurfural, another compound considered as a promising a biofuel candidate.
The production of CMF from cellulose was first described in the early 1900s. Currently, various synthetic routes are known in the art to produce CMF. CMF is typically produced as an oily residue that can be purified by distillation. A liquid form of CMF is typically obtained from the distillation. See e.g., Szmant & Chundury, J. Chem. Tech. Biotechnol. 1981, 31, 205-212; Liu et al., J. Phys. Chem. A, 2011, 115, 13628-13641; and U.S. Pat. No. 7,829,732. The liquid CMF can then be further used in one or more of the reactions described above to produce, for example, fuels and fuel precursors.
The liquid form of CMF and other 5-(halomethyl)furfurals, however, can present several challenges on commercial scale with respect to handling, transportation and storage of the material. Thus, what is needed in the art are solid forms of 5-(halomethyl)furfurals, such as solid forms of 5-(chloromethyl)furfural, and methods of preparing such solid forms of the compounds.